1. Field of the Invention
The invention relates to a glass or glass ceramic pane that reflects infrared radiation as well as a method for producing it. In particular, the invention relates to a viewing pane for high-temperature applications, such as, for example, a front pane for an oven or a fireplace, as well as fire-protection glazing.
2. Description of Related Art
Panes that reflect infrared radiation, in particular viewing panes for ovens and fireplaces, are known. These are, as a rule, constructed as a substrate made of a glass having a low thermal expansion coefficient or from a glass ceramic. Applied to the substrate glass is a coating that has a lower transmission in the infrared region than in the region of visible light.
Thus, the infrared radiation that passes through the pane is appreciably reduced and both a strong heating of the pane and also a strong heating of the adjoining surroundings are prevented.
Known from practice are, for example, titanium oxide/silicon oxide coatings, in particular interference alternating layer systems, which, however, are not relevant in implementation from an economic viewpoint.
A drawback of the known coatings is, besides the great expense of applying such layers, their low heat resistance; in particular, many known transparent conductive coatings (TCCs) lose their reflecting effect at temperatures above 450 degrees Celsius (° C.).
Furthermore, conventional coatings are only suitable in a limited manner for curved glass ceramics, because it is difficult to furnish a curved glass with a homogeneous layer thickness.
A coating of the blank (i.e., green glass) prior to ceramization and bending, on the other hand, is not possible as a rule, because conventional coatings are damaged or destroyed during ceramization.